Definición de minke en inglés:

sustantivo

The eight-night cruise begins in June - perfect for the midnight sun - and you've a strong chance of seeing minkes, orcas and sperm whales.

As it just so happens - and this is pure coincidence - the meat from the minke, sei and sperm whales analytically slaughtered during the sheerly scientific research program is sold commercially.

So, it looks as though the species of large whales the killer whales did eat were typically calves of other humpback whales or grey whales or minke, and grey whales have recovered and yet we see this decline of other species.